xref: /openbmc/linux/kernel/tsacct.c (revision e3b9f1e8)
1 /*
2  * tsacct.c - System accounting over taskstats interface
3  *
4  * Copyright (C) Jay Lan,	<jlan@sgi.com>
5  *
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  */
18 
19 #include <linux/kernel.h>
20 #include <linux/sched/signal.h>
21 #include <linux/sched/mm.h>
22 #include <linux/sched/cputime.h>
23 #include <linux/tsacct_kern.h>
24 #include <linux/acct.h>
25 #include <linux/jiffies.h>
26 #include <linux/mm.h>
27 
28 /*
29  * fill in basic accounting fields
30  */
31 void bacct_add_tsk(struct user_namespace *user_ns,
32 		   struct pid_namespace *pid_ns,
33 		   struct taskstats *stats, struct task_struct *tsk)
34 {
35 	const struct cred *tcred;
36 	u64 utime, stime, utimescaled, stimescaled;
37 	u64 delta;
38 
39 	BUILD_BUG_ON(TS_COMM_LEN < TASK_COMM_LEN);
40 
41 	/* calculate task elapsed time in nsec */
42 	delta = ktime_get_ns() - tsk->start_time;
43 	/* Convert to micro seconds */
44 	do_div(delta, NSEC_PER_USEC);
45 	stats->ac_etime = delta;
46 	/* Convert to seconds for btime */
47 	do_div(delta, USEC_PER_SEC);
48 	stats->ac_btime = get_seconds() - delta;
49 	if (thread_group_leader(tsk)) {
50 		stats->ac_exitcode = tsk->exit_code;
51 		if (tsk->flags & PF_FORKNOEXEC)
52 			stats->ac_flag |= AFORK;
53 	}
54 	if (tsk->flags & PF_SUPERPRIV)
55 		stats->ac_flag |= ASU;
56 	if (tsk->flags & PF_DUMPCORE)
57 		stats->ac_flag |= ACORE;
58 	if (tsk->flags & PF_SIGNALED)
59 		stats->ac_flag |= AXSIG;
60 	stats->ac_nice	 = task_nice(tsk);
61 	stats->ac_sched	 = tsk->policy;
62 	stats->ac_pid	 = task_pid_nr_ns(tsk, pid_ns);
63 	rcu_read_lock();
64 	tcred = __task_cred(tsk);
65 	stats->ac_uid	 = from_kuid_munged(user_ns, tcred->uid);
66 	stats->ac_gid	 = from_kgid_munged(user_ns, tcred->gid);
67 	stats->ac_ppid	 = pid_alive(tsk) ?
68 		task_tgid_nr_ns(rcu_dereference(tsk->real_parent), pid_ns) : 0;
69 	rcu_read_unlock();
70 
71 	task_cputime(tsk, &utime, &stime);
72 	stats->ac_utime = div_u64(utime, NSEC_PER_USEC);
73 	stats->ac_stime = div_u64(stime, NSEC_PER_USEC);
74 
75 	task_cputime_scaled(tsk, &utimescaled, &stimescaled);
76 	stats->ac_utimescaled = div_u64(utimescaled, NSEC_PER_USEC);
77 	stats->ac_stimescaled = div_u64(stimescaled, NSEC_PER_USEC);
78 
79 	stats->ac_minflt = tsk->min_flt;
80 	stats->ac_majflt = tsk->maj_flt;
81 
82 	strncpy(stats->ac_comm, tsk->comm, sizeof(stats->ac_comm));
83 }
84 
85 
86 #ifdef CONFIG_TASK_XACCT
87 
88 #define KB 1024
89 #define MB (1024*KB)
90 #define KB_MASK (~(KB-1))
91 /*
92  * fill in extended accounting fields
93  */
94 void xacct_add_tsk(struct taskstats *stats, struct task_struct *p)
95 {
96 	struct mm_struct *mm;
97 
98 	/* convert pages-nsec/1024 to Mbyte-usec, see __acct_update_integrals */
99 	stats->coremem = p->acct_rss_mem1 * PAGE_SIZE;
100 	do_div(stats->coremem, 1000 * KB);
101 	stats->virtmem = p->acct_vm_mem1 * PAGE_SIZE;
102 	do_div(stats->virtmem, 1000 * KB);
103 	mm = get_task_mm(p);
104 	if (mm) {
105 		/* adjust to KB unit */
106 		stats->hiwater_rss   = get_mm_hiwater_rss(mm) * PAGE_SIZE / KB;
107 		stats->hiwater_vm    = get_mm_hiwater_vm(mm)  * PAGE_SIZE / KB;
108 		mmput(mm);
109 	}
110 	stats->read_char	= p->ioac.rchar & KB_MASK;
111 	stats->write_char	= p->ioac.wchar & KB_MASK;
112 	stats->read_syscalls	= p->ioac.syscr & KB_MASK;
113 	stats->write_syscalls	= p->ioac.syscw & KB_MASK;
114 #ifdef CONFIG_TASK_IO_ACCOUNTING
115 	stats->read_bytes	= p->ioac.read_bytes & KB_MASK;
116 	stats->write_bytes	= p->ioac.write_bytes & KB_MASK;
117 	stats->cancelled_write_bytes = p->ioac.cancelled_write_bytes & KB_MASK;
118 #else
119 	stats->read_bytes	= 0;
120 	stats->write_bytes	= 0;
121 	stats->cancelled_write_bytes = 0;
122 #endif
123 }
124 #undef KB
125 #undef MB
126 
127 static void __acct_update_integrals(struct task_struct *tsk,
128 				    u64 utime, u64 stime)
129 {
130 	u64 time, delta;
131 
132 	if (!likely(tsk->mm))
133 		return;
134 
135 	time = stime + utime;
136 	delta = time - tsk->acct_timexpd;
137 
138 	if (delta < TICK_NSEC)
139 		return;
140 
141 	tsk->acct_timexpd = time;
142 	/*
143 	 * Divide by 1024 to avoid overflow, and to avoid division.
144 	 * The final unit reported to userspace is Mbyte-usecs,
145 	 * the rest of the math is done in xacct_add_tsk.
146 	 */
147 	tsk->acct_rss_mem1 += delta * get_mm_rss(tsk->mm) >> 10;
148 	tsk->acct_vm_mem1 += delta * tsk->mm->total_vm >> 10;
149 }
150 
151 /**
152  * acct_update_integrals - update mm integral fields in task_struct
153  * @tsk: task_struct for accounting
154  */
155 void acct_update_integrals(struct task_struct *tsk)
156 {
157 	u64 utime, stime;
158 	unsigned long flags;
159 
160 	local_irq_save(flags);
161 	task_cputime(tsk, &utime, &stime);
162 	__acct_update_integrals(tsk, utime, stime);
163 	local_irq_restore(flags);
164 }
165 
166 /**
167  * acct_account_cputime - update mm integral after cputime update
168  * @tsk: task_struct for accounting
169  */
170 void acct_account_cputime(struct task_struct *tsk)
171 {
172 	__acct_update_integrals(tsk, tsk->utime, tsk->stime);
173 }
174 
175 /**
176  * acct_clear_integrals - clear the mm integral fields in task_struct
177  * @tsk: task_struct whose accounting fields are cleared
178  */
179 void acct_clear_integrals(struct task_struct *tsk)
180 {
181 	tsk->acct_timexpd = 0;
182 	tsk->acct_rss_mem1 = 0;
183 	tsk->acct_vm_mem1 = 0;
184 }
185 #endif
186